Re: something like linum.el ought to be added

[Markus Triska <markus.triska@gmx.at>]

Richard Stallman <rms@gnu.org> writes:

> Is it efficient enough?

Many users have reported good success, and it works well for me too.
Please let me know if it doesn't work for you.

> Preserving overlays on the other parts of the buffer won't things
> speed up

Since those overlays can be reused when re-visiting the parts of the
buffer they were created for, this can speed things up since it avoids
re-creation of overlays and intermediate garbage collection.

> It would be much better if it worked from after-change-functions, and
> reassigned overlays only for the lines that really need it.

Line numbers should also be updated after scrolling, M-x goto-line and
many other functions that change the visible portion. The current
method is more reliable and works, I hope, sufficiently well.

> I agree those are good ideas.

Implemented in version 0.9b, available from the given link.